What is Fractionated Morse?

The plaintext is enciphered with morse code, with an x separating each letter and xx separating each word. Then, a keyword alphabet is written, and dots, dashes, and Xes are written under it in groups of three.

Finally, the morse code of the plaintext is written vertically in groups of three, left to right. Each group of three is matched to its equivalent in the keyword alphabet code.

Example

Plaintext: RIP VAN WINKLE

Morse code of the above: .-.x..x.--.xx...-x.-x-.xx.--x..x-.x-.-x.-..x.

KATSILBCDEFGHJMNOPQRUVWXYZ
.---------xxxxxxxx
...---xxx...---xxx...---xx
.-x.-x.-x.-x.-x.-x.-x.-x.-

Encipher step:

.xx-x..-x-.
---..xxx--x
..-x.xxx-.--x..
SQRGQLLGRNCCLSB

Ciphertext SQRGQ LLGRN CCLSB